First commit

Signed-off-by: Mattias Andrée <maandree@kth.se>

9 files changed, 265 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..983233b
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,10 @@
+*\#*
+*~
+*.o
+*.a
+*.lo
+*.so
+*.so.*
+*.su
+*.dll
+*.dylib
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..c437151
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,15 @@
+ISC License
+
+© 2019 Mattias Andrée <maandree@kth.se>
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..924776d
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,63 @@
+.POSIX:
+
+CONFIGFILE = config.mk
+include $(CONFIGFILE)
+
+OS = linux
+# linux = Linux
+# macos = Mac OS
+include $(OS).mk
+
+LIB_MAJOR = 1
+LIB_MINOR = 0
+LIB_VERSION = $(LIB_MAJOR).$(LIB_MINOR)
+
+
+HDR =\
+	internal.h
+
+OBJ =\
+	print_backtrace.o\
+	save_backtrace.o
+
+LOBJ = $(OBJ:.o=.lo)
+
+
+all: liberror-backtrace.a liberror-backtrace.$(LIBEXT)
+$(OBJ): $(@:.o=.c) $(HDR)
+$(LOBJ): $(@:.lo=.c) $(HDR)
+
+liberror-backtrace.a: $(OBJ)
+	-rm -f -- $@
+	$(AR) rc $@ $(OBJ)
+	$(AR) s $@
+
+liberror-backtrace.$(LIBEXT): $(LOBJ)
+	$(CC) $(LIBFLAGS) -o $@ $(LOBJ) $(LDFLAGS)
+
+.c.o:
+	$(CC) -c -o $@ $< $(CFLAGS) $(CPPFLAGS)
+
+.c.lo:
+	$(CC) -c -o $@ $< -fPIC $(CFLAGS) $(CPPFLAGS)
+
+install: liberror-backtrace.a liberror-backtrace.$(LIBEXT)
+	mkdir -p -- "$(DESTDIR)$(PREFIX)/lib"
+	mkdir -p -- "$(DESTDIR)$(PREFIX)/licenses/liberror-backtrace"
+	cp -- liberror-backtrace.a "$(DESTDIR)$(PREFIX)/lib"
+	cp -- liberror-backtrace.$(LIBEXT) "$(DESTDIR)$(PREFIX)/lib/liberror-backtrace.$(LIBMINOREXT)"
+	ln -sf -- liberror-backtrace.$(LIBMINOREXT) "$(DESTDIR)$(PREFIX)/lib/liberror-backtrace.$(LIBMAJOREXT)"
+	ln -sf -- liberror-backtrace.$(LIBMINOREXT) "$(DESTDIR)$(PREFIX)/lib/liberror-backtrace.$(LIBEXT)"
+	cp -- LICENSE "$(DESTDIR)$(PREFIX)/licenses/liberror-backtrace"
+
+uninstall:
+	-rm -f -- "$(DESTDIR)$(PREFIX)/lib/liberror-backtrace."*
+	-rm -rf -- "$(DESTDIR)$(PREFIX)/licenses/liberror-backtrace"
+
+clean:
+	-rm -f -- *.o *.lo *.a *.so *.so.* *.su *.test
+
+.SUFFIXES:
+.SUFFIXES: .c .o .lo .a
+
+.PHONY: all install uninstall clean
diff --git a/config.mk b/config.mk
new file mode 100644
index 0000000..fa0eba8
--- /dev/null
+++ b/config.mk
@@ -0,0 +1,6 @@
+PREFIX    = /usr
+MANPREFIX = $(PREFIX)/share/man
+
+CPPFLAGS = -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_XOPEN_SOURCE=700
+CFLAGS   = -std=c11 -Wall -pedantic
+LDFLAGS  = -s -lunwind -ldw
diff --git a/internal.h b/internal.h
new file mode 100644
index 0000000..e2d1652
--- /dev/null
+++ b/internal.h
@@ -0,0 +1,25 @@
+/* See LICENSE file for copyright and license details. */
+#include <alloca.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+
+struct liberror_error {
+	struct liberror_backtrace *backtrace;
+};
+
+
+struct liberror_backtrace {
+	size_t refcount;
+	size_t n;
+	uintptr_t rips[];
+};
+
+
+void liberror_print_backtrace(struct liberror_error *, FILE *, const char *);
+int liberror_save_backtrace_(struct liberror_error *);
diff --git a/linux.mk b/linux.mk
new file mode 100644
index 0000000..c9f74a0
--- /dev/null
+++ b/linux.mk
@@ -0,0 +1,5 @@
+LIBEXT = so
+LIBFLAGS = -shared -Wl,-soname,libkeccak.$(LIBEXT).$(LIB_MAJOR)
+
+LIBMAJOREXT = $(LIBEXT).$(LIB_MAJOR)
+LIBMINOREXT = $(LIBEXT).$(LIB_VERSION)
diff --git a/macos.mk b/macos.mk
new file mode 100644
index 0000000..b475197
--- /dev/null
+++ b/macos.mk
@@ -0,0 +1,5 @@
+LIBEXT = dylib
+LIBFLAGS = -dynamiclib
+
+LIBMAJOREXT = $(LIB_MAJOR).$(LIBEXT)
+LIBMINOREXT = $(LIB_VERSION).$(LIBEXT)
diff --git a/print_backtrace.c b/print_backtrace.c
new file mode 100644
index 0000000..d8a53e8
--- /dev/null
+++ b/print_backtrace.c
@@ -0,0 +1,75 @@
+/* See LICENSE file for copyright and license details. */
+#include "internal.h"
+
+#include <elfutils/libdwfl.h>
+
+
+void
+liberror_print_backtrace(struct liberror_error *error, FILE *fp, const char *indent)
+{
+	struct liberror_backtrace *backtrace;
+	int saved_errno = errno, full_paths, lineno;
+	char *debuginfo_path = NULL, *env;
+	Dwarf_Addr ip;
+	Dwfl_Callbacks callbacks;
+	Dwfl *dwfl = NULL;
+	Dwfl_Line *line = NULL;
+	Dwfl_Module *module = NULL;
+	const char *filename = NULL, *p;
+	const char *funcname = NULL;
+	size_t i;
+
+	if (!error)
+		return;
+
+	backtrace = error->backtrace;
+	if (!backtrace)
+		return;
+
+	memset(&callbacks, 0, sizeof(callbacks));
+
+	callbacks.find_elf       = dwfl_linux_proc_find_elf;
+	callbacks.find_debuginfo = dwfl_standard_find_debuginfo;
+	callbacks.debuginfo_path = &debuginfo_path;
+
+	env = getenv("LIBERROR_FULL_PATHS");
+	full_paths = env && (*env == 'Y' || *env == 'y' || *env == '1');
+
+	dwfl = dwfl_begin(&callbacks);
+
+	if (dwfl) {
+		if (dwfl_linux_proc_report(dwfl, getpid()) ||
+		    dwfl_report_end(dwfl, NULL, NULL)) {
+			dwfl_end(dwfl);
+			dwfl = NULL;
+		}
+	}
+
+	for (i = 0; i < backtrace->n; i++) {
+		ip = (Dwarf_Addr)backtrace->rips[i];
+
+		if (dwfl) {
+			module   = dwfl_addrmodule(dwfl, ip);
+			funcname = module ? dwfl_module_addrname(module, ip) : NULL;
+			line     = dwfl_getsrc(dwfl, ip);
+			if (line) {
+				filename = dwfl_lineinfo(line, &(Dwarf_Addr){0}, &lineno, NULL, NULL, NULL);
+				if (!full_paths && (p = strrchr(filename, '/')))
+					filename = &p[1];
+			}
+		}
+
+		fprintf(fp, "%s%s 0x%016"PRIxPTR": %s",
+		        indent, !i ? "at" : "by",
+			(uintptr_t)ip,
+		        funcname ? funcname : "???");
+		if (line)
+			fprintf(fp, " (%s:%i)\n", filename, lineno);
+		else
+			fprintf(fp, "\n");
+	}
+
+	if (dwfl)
+		dwfl_end(dwfl);
+	errno = saved_errno;
+}
diff --git a/save_backtrace.c b/save_backtrace.c
new file mode 100644
index 0000000..e366abf
--- /dev/null
+++ b/save_backtrace.c
@@ -0,0 +1,61 @@
+/* See LICENSE file for copyright and license details. */
+#include "internal.h"
+
+#define UNW_LOCAL_ONLY
+#include <libunwind.h>
+
+
+struct partial {
+	uintptr_t rips[8];
+	struct partial *next;
+};
+
+
+int
+liberror_save_backtrace(struct liberror_error *error)
+{
+	struct liberror_backtrace *backtrace = NULL;
+	unw_word_t rip;
+	unw_cursor_t cursor;
+	unw_context_t context;
+	size_t i = 0;
+	struct partial *current, head;
+	int saved_errno = errno;
+	int ret = -1;
+
+	if (unw_getcontext(&context))
+		goto out;
+	if (unw_init_local(&cursor, &context))
+		goto out;
+
+	current = &head;
+
+	for (; unw_step(&cursor) > 0; i++) {
+		if (!(i & 7))
+			current = current->next = alloca(sizeof(*current));
+		if (unw_get_reg(&cursor, UNW_REG_IP, &rip))
+			goto out;
+		current->rips[i & 7] = (uintptr_t)rip;
+	}
+
+	backtrace = malloc(offsetof(struct liberror_backtrace, rips) + i * sizeof(*backtrace->rips));
+	if (!backtrace)
+		goto out;
+	backtrace->refcount = 1;
+
+	backtrace->n = i;
+	current = &head;
+	for (i = 0; i < backtrace->n; i++) {
+		if (!(i & 7))
+			current = current->next;
+		backtrace->rips[i] = current->rips[i & 7];
+	}
+
+	ret = 0;
+out:
+	if (error->backtrace && !--error->backtrace->refcount)
+		free(error->backtrace);
+	error->backtrace = backtrace;
+	errno = saved_errno;
+	return ret;
+}